Diet and brain: every vegetable has its time
Diet helps the brain in old age and harms the youngAlexey Tymoshenko, GZT.RU
Having studied two fundamentally different ways of prolonging life (diet and genetic manipulation) in animals, experts from Princeton University (USA) came to the conclusion that limiting the amount of food consumed allows you to live longer, with less memory deterioration in old age, but in youth the ability to remember new things will be significantly reduced.
Model organisms
The study described in detail in the scientific journal PLOS Biology (Amanda L. Kauffman et al., Insulin Signaling and Dietary Restriction Differently Influence the Decline of Learning and Memory with Age), as already noted above, was conducted on animals. The choice of experimental organisms for an outsider might seem strange, but scientists knew what they were doing. The roundworm Caenorhabditis elegans, or simply C.elegans, has long been a favorite object for gerontologists, specialists studying aging processes, and neuroscientists.
In numerous experiments that have been performed on Caenorhabditis elegans all over the world for decades, molecular biologists have been able to study the role of many different genes in the aging process, simultaneously checking the role of such a factor as nutrition. The data obtained on worms were consistent with those obtained by scientists working on mice, and a significant part of the material collected on all animals turned out to be quite close to humans.
The fact that a worm is many times simpler than a human is not so important in the study of processes at the cellular level. A number of processes, including aging, are caused by failures at the level of individual cells, therefore in some cases it is enough not even worms, but even unicellular organisms. Experiments with yeast, for example, allowed us to investigate the disease that struck the famous British astrophysicist Stephen Hawking.
But how to study memory on worms? It's very simple: scientists first withstood Caenorhabditis elegans without food for a while, and then gave them food at the same time with a 10% solution of butyl alcohol. Then, when the animals got hungry again, butyl alcohol dripped next to them – and the worms began to crawl towards the smell, which normally meant nothing to them.
Memory Basics
The researchers compared several different lines (the so-called genetically different "breeds" of worms) of animals with different genotypes. Some worms were genetically engineered to consume less food, while others differed in the structure of receptors that ensure the response of cells to insulin.
Differences in insulin receptors have previously been associated with changes in the ability to remember new information in both worms and mice. In addition, a number of experiments indicated the connection of insulin receptors with memory loss in old age.
We emphasize especially that both worms and humans have insulin-responsive receptors. The researchers studied not so much the worms themselves as the processes occurring inside nerve cells, which are more or less similar in all animals with a nervous system. Designers who test the operation of car parts also often use a special test bench rather than an assembled car; biologists and doctors use genetically modified animals as "test benches".
The results of the experiments showed that worms imitating constant dieting lose their ability to learn faster in youth, but they age more slowly in the future. With the same animals that underwent genetic modification and received "improved" insulin receptors, everything was different: they showed better results in their youth, but then aged on a par with ordinary individuals.
Molecular foundation
It might seem that the result was pretty much obvious. After all, it is well known that dieting reduces the risk of developing cardiovascular diseases, and obesity, on the contrary, contributes to the development of atherosclerosis. But the general state of the body is one thing, and molecular processes in nerve cells are quite another.
The value of the work of American biologists is not only that scientists have shown different effects on the memory of diet and genetic differences. Along the way, the researchers also tracked a number of indicators that display the activity of nerve cells after learning, which are directly related to the consolidation of information in memory. And thus it was shown that intracellular processes play a key role in the influence of diet on the brain.
Portal "Eternal youth" http://vechnayamolodost.ru19.05.2010